The long-term goal of this research project is to isolate and characterize the various membrane antigens associated with human leukemia and lymphoma cells. Since leukemia and lymphoma cells usually represent monoclonal proliferations of various lymphoid and myeloid series cells, antisera elicited to these malignant cells will also be studied for their ability to define normal cell antigens. We will also attempt fo devise and improve our present methods for the detection of leukemia and lymphoma cells and to more precisely classify these diseases. Emphasis will be placed on those antigens which will define subpopulations of lymphoid or myeloid cells and on antigens which may distinguish certain stages of differentiation of these cell types.